gpredict: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On CentOS possible default full paths are:

/usr/bin/gpredict - from package: gpredict

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/bin/gpredict - from package: gpredict

You may install the required package with command apt-get install {package}

Error in other languages:
gpredict: bevel nie gevind nie
gpredict: comandă negăsită
gpredict: comando não encontrado
gpredict: commande introuvable
gpredict: command not found
gpredict: käsku ei ole
gpredict: không tìm thấy lệnh
gpredict: komanda nerasta
gpredict: Kommando nicht gefunden.
gpredict: kommandot finns inte
gpredict: komut yok
gpredict: nie znaleziono polecenia
gpredict: níor aimsíodh an t-ordú
gpredict: no se encontró la orden
gpredict: no s'ha trobat l'ordre
gpredict: opdracht niet gevonden
gpredict: parancs nem található
gpredict: perintah tidak ditemukan
gpredict: príkaz nenájdený
gpredict: příkaz nenalezen
gpredict: команда не найдена
gpredict: командата не е открита
gpredict: 命令找不到
gpredict: コマンドが見つかりません